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2 years ago

What does -9.8 m/s mean? And what does it mean if something has a negative velocity?

1 answer:

4 0

I can't guess what -9.8 m/s means until you tell me where it came from,
or what 'm/s' means.

If perhaps it has something to do with the acceleration of gravity on Earth,
then the correct figure is ' -9.8 m/s² '. That means that any object that
has no other force acting on it except gravity has its speed changing by
9.8 meters per second every second. Since it's gravity doing the job,
then the object's speed is either increasing down, or decreasing up.

If an object has negative velocity, then it's moving in the direction opposite
to the direction that you decided to call positive when you started doing the
problem.

For example, if you decide that up is positive and down is negative, and
then somebody drops a stone from the top of a tall building, then the
gravitational force on the stone is negative (pointing down), its velocity
is negative (it's falling towards down), and its acceleration is negative (its
speed towards down is getting faster and faster). Everything is negative,
only because you decided that up is positive and down is negative. It's
nothing to be worried about.

You might be interested in

A 12 kg block is accelerating at the rate of 9.0 m/s? while being acted on by two forces.

Aliun [14]

Answer:

See below

Explanation:

F = ma

F = 12 * 9 = 108 N

108 N needed add 30 N more east

8 0

6 months ago

Find the voltage change when: a. An electric field does 12 J of work on a 0.0001-C charge. b. The same electric field does 24 J

kondaur [170]

Explanation:

Given that,

(a) Work done by the electric field is 12 J on a 0.0001 C of charge. The electric potential is defined as the work done per unit charged particles. It is given by :

$V=\dfrac{W}{q}$

$V=\dfrac{12}{0.0001}$

$V=12\times 10^4\ Volt$

(b) Similarly, same electric field does 24 J of work on a 0.0002-C charge. The electric potential difference is given by :

$V=\dfrac{W}{q}$

$V=\dfrac{24}{0.0002}$

$V=12\times 10^4\ Volt$

Therefore, this is the required solution.

7 0

2 years ago

The infant's tendency to turn its head toward things that touch its cheek is known as the

katovenus [111]

Answer:

I think it is Rooting Reflex

4 0

2 years ago

Read 2 more answers

A small object carrying a charge of -2.50 nc is acted upon by a downward force of 18.0 nn when placed at a certain point in an e

Vesna [10]

Missing question in the text:
"A.What are the magnitude and direction of the electric field at the point in question?

B.What would be the magnitude and direction of the force acting on a proton placed at this same point in the electric field?"

Solution:

A) A charge q under an electric field of intensity E will experience a force F equal to:

$F=qE$

In our problem we have $q=-2.5 nC=-2.5\cdot 10^{-9} C$ and $F=18 nN = 18 \cdot 10^{-9} N$ , so we can find the magnitude of the electric field:

$E= \frac{F}{q}= \frac{18\cdot 10^{-9}N}{2.5\cdot 10^{-9}C}=7.2 V/m$

The charge is negative, therefore it moves against the direction of the field lines. If the force is pushing down the charge, then the electric field lines go upward.

B) The proton charge is equal to

$e=1.6\cdot 10^{-19} C$

Therefore, the magnitude of the force acting on the proton will be

$F=eE=1.6\cdot 10^{-19} C \cdot 7.2 V/m=1.15 \cdot 10^{-18} N$

And since the proton has positive charge, the verse of the force is the same as the verse of the field, so upward.

7 0

2 years ago

If something is traveling at 20 m/s constant velocity, is it in equilibrium? If a projectile is launched at a velocity of 20 m/s

Irina18 [472]

If something is traveling at 20 m/s constant speed AND its direction isn't changing, then its velocity is constant. Another way to say that is: Its acceleration is zero. Zero acceleration means zero NET force acting on the object, or a group of BALANCED forces acting on it, also called EQUILIBRIUM. The required answer is: YES.

If a real projectile is launched, the force of gravity acts on it vertically downward. There's no upward force acting on it to balance gravity. Therefore, the forces on the projectile are NOT balanced, there IS a net vertical force on it, and it's NOT in equilibrium. Too bad.

3 0

2 years ago